The biologic and chemical characteristics of lymphoid and cell surface antigens are under investigation. A method for rapidly isolating the B lymphocyte subpopulation of human peripheral blood lymphocytes has been developed allowing genetic characterization of B lymphocyte antigens. Genes controlling these antigens are linked to genes controlling the HLA antigens. The B cell antigens have been found on Ig-bearing cells and are not demonstrable by cytotoxicity tests on T cells or the Fc positive K cell population. B-cell antigens isolated by immunoprecipitation techniques have been found to have two molecular components having a molecular weight of 29,000 and 34,000 daltons. Analysis of B-cell antigen frequencies in several disease conditions have been performed. A B-cell antigen identified and specific for the diseases gluten sensitive enteropathy and dermatitis herpetiformus has been found to be under the control of a gene or genes not linked to the HLA complex and appears to be a receptor for gluten, the disease causing agent. Forty N-terminal amino acids of the HLA antigens of the A locus and the B locus demonstrate near complete homology. Amino acid sequence analysis of the B cell antigens demonstrate distinct differences from the HLA antigens. BIBLIOGRAPHIC REFERENCES: Nelson, D. L., Strober, W., Abelson, L. D., Bundy, B. M., and Mann, D. L.: Distribution of alloantigens on human Fc receptor bearing lymphocytes: the presence of B-cell alloantigens on sIg positive but not sIg negative lymphocytes. J. Immunol. 118: 943-946, 1977. Nilsson, S., Schwartz, B., Waxdal, M., Green, I., Cullen, S. and Mann, D.: A human alloantiserum detects Ia-like molecules on chronic lymphocytic leukemia cells. J. Immunol. 118: 1271-1274, 1977.